The Broan QTX110S bathroom vent fans are the quietest product on the market representing the ultimate in bath fan solutions for today's homes. The Sensaire® technology detects rapid increases in moisture levels at the ceiling, where steam and humidity naturally rise. This humidity sensing fans turn on and off automatically to help prevent cosmetic and structural problems associated with excess moisture. Just beneath the drop-down grille are easy-to-adjust sensitivity and run-time controls. Since you never have to worry about turning the fan on, Broan Ultra Silent™ is ideal for problem areas in residential, institutional and light-commercial applications. The exclusive Sensaire® technology is a perfect solution for high-traffic bathrooms, or a kid's bathroom.